This invention concerns air cleaning systems or equipment that are used to remove undesirable hazardous, radioactive, or toxic particles, vapors or gases that can emanate, disburse, evaporate or otherwise become suspended in the air breathing zone, usually near the source of such hazardous or undesirable airborne materials. Such materials have the form, for example, of asbestos fibers, or toxic organic solvents or reactants such as benzene, totulene, or ketones, or smokes and fumes such as that emitted from welding, or fine particles such as those generated and propelled into the air from sanding paint, e.g., lead based, rust, corrosion or other surface coating, many of which may also have radioactive elements adhering thereto which emit Alpha, Beta or Gamma radiation. The removal of these harmful airborne substances from the air breathing zone or area of generation is necessary to protect both personnel and the environment from their harmful effects.
The apparatus typically employed for removing these contaminants comprises air filtration, cleansing, scrubbing, or washing systems or units, or other such equipment. These systems function to remove the contamination by such means in filters, adsorbers, absorbers or washers and the air exits the system in a cleaner condition than when it entered. At times, the air flow must be directed through several filters, scrubbers, adsorbers or adsorbers to effectively remove the contaminant to a level considered safe enough for release to the atmosphere for breathing.
Typically the systems available to perform this air cleaning are comprised of a prime mover or air blower unit including a motor, usually electric, but also may be hydraulic or compressed air or internal combustion, with the motor powering a fan or blower device. The motor may connect to the blower or fan either directly to the motor shaft or via a belt and pulley or gear or clutch train which may give an increase or decrease in the motor applied speed or torque. One arrangement has the blower air discharge or positive pressure side connected to a housing or plenum box that contains the filter, adsorber or other desired air cleansing device or a combination thereof. The connection between the blower and the filter housing is most commonly made by a piece of duct work, or a boot of steel or fabric, or rubber or composite material. Since the blower discharge is usually smaller than the filter housing inlet there is commonly a transition from small to large that is called a plenum that directs the air flow into and through the filter housing.
This type connection (transition/plenum) is commonly repeated on the downstream, outlet side of the filter housing to allow the routing of the discharge air flow through a duct work to a desired location. An alternate configuration of such a system is to locate the blower fan and motor on the downstream side of the filter housing such that the blower creates a negative pressure on the filter housing and causes air to flow through the filtration mechanism.
The most common denominator in such prior systems is that the components are assembled into a fixed arrangement of the filter train suitable for an intended purpose and are confined to that arrangement only. They cannot readily be reconfigured by the user to perform some other air cleaning function or to allow relocation of the air filter housings or modules containing the air cleaning elements in relation to each other and to the blower/motor, or to provide for the addition or removal of filter housings or other components should changing job situations require a modification of the air filtration train by the rapid addition or removal of air cleaning elements, or the rearrangement of the component sequence.
Additionally, the components cannot readily be removed from the common mounting frame to allow their use in some other air cleaning system. If a component of such a system could be removed, it would be difficult to reconnect it to another component because it would not be designed to mate with another part and would require affixing inlet and outlet plenums of a type that would facilitate connecting that component to another with some type of air duct or hose. In this regard, the inlet connections on these systems are usually of a fixed design limiting the size, or number or location to those inlets built into the system. Also, the connecting of accessories or appliances or work assisting devices to the air inlet of these units must be accomplished by interconnecting the desired appliance to the inlet of the air cleaning system with a duct, hose, flexible duct or other such conduit for interconnecting and promoting air flow between the accessory and air cleaner system.
These accessories or appliances may be, e.g., a Capture Velocity Hood, or Down-draft Table, or Funnel Arm or other such desired device or appliance designed to direct the air flow so as to contain the flow and entrapped contaminants in the air stream until they are removed by the air cleaning elements of the system. The failure of these typical systems to allow easy component relocation or reconfiguration, or the simple interconnection of various components and/or the direct attachment of accessories or appliances to the system for performance enhancement is a serious drawback to their practical utility.